Avalanna Routh, also known as "Mrs. Bieber," lost her battle with cancer on Wednesday.

Justin Bieber received sad news on Wednesday, tweeting to his 28 million-plus followers that a 6-year-old super fan had died.

Avalanna Routh, dubbed “Mrs. Bieber” by her friends and family, lost her battle with cancer on Wednesday morning. “Our darling Avalanna went to Heaven this morning. Oh Avalanna, the brightest star -- you took our hearts with you, our greatest Love,” her parents posted on Twitter early Wednesday.

“Just got the worst news ever. One of the greatest spirits I have ever known is gone. Please pray for her family and for her,” Bieber tweeted. “RIP Avalanna. I love you.”

Bieber paid the tyke a visit earlier this year in New York after a family friend created a Facebook petition “Get Avalanna to Meet Justin Bieber.” Additional meetings ensued, including a joint appearance on the Today show. Watch the video below.

Prior to meeting the pop star, the staff at the Dana-Farber/Children’s Hospital Cancer Center had thrown a fake wedding for Avalanna – who was widely known as a huge Bieber fan – that included a red T-shirt that read “Future Mrs. Bieber,” flowers, a wedding cake and a singer, according to The Los Angeles Times.

Avalanna was diagnosed with a rare and aggressive cancer at 9 months old called an AT/RT, or atypical teratoid/rhabdoid tumor. According to Dr. Charles Roberts, the AT/RT is “a cancer that strikes babies and toddlers and arises in the brain… We are still having an extremely difficult time curing this type of cancer.” Though most of those diagnosed with the ailment die within a year, Routh lived to be 6 years old.

After meeting Routh for the first time, Bieber told fans that it was “one of the best things I have ever done. She was AWESOME! Feeling really inspiried now #MrsBieber.”

On Wednesday, he asked followers to “please show respect to her and her family. Say a prayer for her and for them.